Owing to their potential applications, as well as their structural diversity, the discovery of novel secondary metabolites from insect-associated fungi has been of interest to researchers in recent years. The aim of this study was therefore to estimate the diversity of fungi associated with fungus-growing termites and bioprospecting these for potential secondary metabolites. In total, 18 fungal species were isolated and described from the gut and comb of Macrotermes barneyi based on 18S rDNA gene sequence analysis. Antimicrobial activity assays were carried out on all the known fungi, and nine isolates were recorded as active against pathogenic fungi. Xylaria escharoidea, the best performing isolate, was grown at laboratory scale and 4,8-dihydroxy-3,4-dihydronaphthalen-1(2H) was isolated and characterized. The minimum inhibitory concentration of this isolated compound against tested pathogenic organisms was found to be 6.25 μg. In addition, molecular docking studies have revealed that 4,8-dihydroxy-3,4-dihydronaphthalen-1(2H) is a prominent antibacterial agent with a marked interaction with key residues on protein A (agrAC ) that regulates the accessory gene. The findings of this study support the drug discovery of antimicrobial properties in insect-associated fungi, which may lead to novel secondary metabolites. This article is protected by copyright. All rights reserved.

中文翻译：

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来自真菌生长白蚁 Macrotermes barneyi 的真菌分离物的多样性和来自 Xylaria escharoidea 的生物活性化合物的表征

由于它们的潜在应用以及它们的结构多样性，近年来研究人员对昆虫相关真菌中新型次级代谢产物的发现产生了兴趣。因此，本研究的目的是估计与真菌生长的白蚁相关的真菌的多样性，并对这些真菌进行生物勘探以寻找潜在的次生代谢物。基于 18S rDNA 基因序列分析，总共从大白蚁的肠道和鸡冠中分离和描述了 18 种真菌。对所有已知真菌进行了抗微生物活性测定，并记录了 9 个分离株对病原真菌具有活性。Xylaria escharoidea 是表现最好的分离株，在实验室规模生长，4,8-dihydroxy-3,4-dihydronaphthalen-1(2H) 被分离和表征。发现这种分离的化合物对测试的病原生物的最小抑制浓度为 6.25 μg。此外，分子对接研究表明，4,8-dihydroxy-3,4-dihydronaphthalen-1(2H) 是一种突出的抗菌剂，与调节辅助基因的蛋白 A (agrAC) 上的关键残基有显着的相互作用。这项研究的结果支持昆虫相关真菌抗菌特性的药物发现，这可能会导致新的次级代谢产物。本文受版权保护。版权所有。4-dihydronaphthalen-1(2H) 是一种突出的抗菌剂，与调节辅助基因的蛋白 A (agrAC) 上的关键残基有显着的相互作用。这项研究的结果支持昆虫相关真菌抗菌特性的药物发现，这可能会导致新的次级代谢产物。本文受版权保护。版权所有。4-dihydronaphthalen-1(2H) 是一种突出的抗菌剂，与调节辅助基因的蛋白 A (agrAC) 上的关键残基有显着的相互作用。这项研究的结果支持昆虫相关真菌抗菌特性的药物发现，这可能会导致新的次级代谢产物。本文受版权保护。版权所有。